Evidence is mixed on self-exams

Conflicting news coverage has heightened the confusion over whether women should do breast self-exams.

"Breast self-exam has no benefit," one headline proclaimed.

"Breast self-exam key in catching what mammogram may miss," another said.

A scientific review, published in August by the Cochrane Library, highlighted the downside of doing breast self-exams: Women taught to perform the monthly ritual wind up having unnecessary biopsies. They are about twice as likely to undergo biopsies that won't find cancerous tumors, according to two studies tracking hundreds of thousands of women in China and Russia.

Researchers have learned that self-exams aren't at all simple. The technique is complicated and difficult to learn to do well. Guidelines on how to do them correctly have evolved, leaving many women and doctors with outdated ideas.

Further, decades of research still have not produced good evidence that self-exams make any difference in breast cancer survival.

"Not only do the trials not find a benefit, the trials demonstrate harm in terms of increased physician visits and benign breast biopsies," said Dr. Nancy Baxter, a University of Toronto surgeon who reviewed the evidence on self-exams for the Canadian Task Force on Preventive Health Care. She said self-exams may not reveal tumors early enough to improve survival.

Given the lack of evidence, the American Cancer Society stopped advocating self-exams in 2003. The U.S. Preventive Services Task Force considers the exams unproven. And the Canadian Task Force on Preventive Health Care has recommended against routine teaching of breast self-exams since 2001.

Unnecessary biopsies may not be the only hidden cost.

"One danger of pushing breast self-exams on patients is that they may be falsely reassured by it and opt out of their mammograms," said Dr. Heidi Nelson, medical director of the Providence Women and Children's Program in Portland, Ore.

But some evidence does suggest that self-exams done properly could make a difference.

For instance, they provide a means to search for tumors in outer parts of the breast where mammography may not reach. About half of breast cancers develop in the upper-outer quadrant of the breast, which is largely inaccessible to mammography scanners.

A small study in Canada in 1997 found that self-exams seemed to improve survival among a subset of women using proper technique. The preferred method, known as the vertical strip, three-pressure test, has proved the most sensitive and least likely to produce false alarms, said Dr. Elizabeth Steiner, director of the breast health education program at Oregon Health & Science University.

In the largest and most influential study to date, involving 266,000 women in Shanghai, researchers taught an inferior method of exams, Steiner said. She said that could partly explain why the Shanghai study failed to find improved survival.

If a woman decides to do self-exams, Steiner said, it's important to learn to do them right -- and do them every month without fail.

She encourages women to schedule an appointment devoted to learning the technique, which should take at least a half-hour.

Steiner said not all doctors are up to speed on breast exam technique, which calls for lying down -- not standing in the shower, the practice pushed for years by physicians and even anti-breast cancer groups.